This invention relates to wheel nuts and, more particularly, to an improved wheel nut for retaining a wheel to a hub and simultaneously retaining a wheel cover in position on the wheel.
There were, prior to the present invention, basically three types of wheel nuts, often referred to as wheel lugs, for retaining vehicle wheels to hubs. The "hub" refers to the end of the axle where the wheel is mounted. The hub has a plurality of threaded studs, such as five, extending outwardly therefrom and a wheel, having five apertures, is mounted on the hub by aligning the apertures in the wheel with the studs on the hub. The wheel, of course, is provided with a circumferentially mounted tire. Once the wheel is mounted on the hub, wheel nuts are threaded onto the studs to retain the wheel on the hub. A decorative wheel cover may then be removably force fit onto the wheel.
The first type of wheel nut heretofore used was a thin, flat disc-like steel member having a central threaded bore therethrough. The nut had six peripheral flat surfaces, called wrench flats, and the nut was hexagonal in plan view. This first type of wheel nut is the oldest type which is still in widespread use.
A second type of wheel nut was the decorative wheel nut which was formed as a single piece chrome plated elongated rod-like member. This one-piece chrome plated wheel nut included an internally threaded bore which extended almost the full length of the nut but the bore was closed at one end. This wheel nut also had a plurality of wrench flats, typically six, so that the wheel nut could be tightened onto the conventional stud extending outwardly of the hub to thereby secure the wheel to the hub. This type of chrome plated wheel nut is commercially available.
A third type of wheel nut utilized a steel nut body to which a stainless steel decorative cap was attached. The nut body was similar to the first type of wheel nut including a central threaded bore and a plurality of wrench flats. The decorative cap covered one end of the bore as well as the wrench flats. Thus the cap protected the end of the stud from damage due to weather, impact or the like and, when the capped wheel nuts were threaded on to the studs to secure the wheel to the hub, essentially only the decorative stainless steel cap was visible. The capped wheel nut is also commercially available.
Numerous types of "wheel covers" or "hub caps" have been marketed to enhance the appearance of the wheel mounted on the hub. Where the first type of lug nuts are utilized, the wheel cover or hub cap is attached to the wheel to hide and protect the nuts and the studs. Where either the one-piece chrome plated wheel nuts or the capped wheel nuts are utilized, two alternate types of covers were used. In the first type, there were a plurality of apertures in the wheel cover so that when the wheel cover is in place on the wheel, the capped wheel nuts (or alternatively the chrome wheel nuts) extend through the apertures in the wheel cover. In the second type there were no apertures in the cover but the cover was of a sufficiently small diameter so that there was no interference between the wheel cover and the wheel nuts.
Typically, the wheel cover has a plurality of resilient protrusions which engage the wheel for retaining the wheel cover on the wheel. Occasionally, however, a wheel cover will fall off the wheel when the vehicle is driven on bumpy roads or in the event of improper placement of the wheel cover on the wheel such as after changing a tire or the like.
There have been various attempts to solve the problem of inadvertent removal of (or even theft of) the wheel cover. As discussed in greater detail, none of these has been totally satisfactory.
In addition, as wheel covers become more decorative and more expensive, a problem has arisen in that many wheel covers are stolen since typically a flat-bladed screwdriver may be sufficient to dislodge the wheel cover from the wheel. This is especially true with new cars where wheel covers are often stolen from the car dealer. Hence many cars are shipped from the factory with wheel covers in the trunk.